ESPN MLB

If baseball is the national pastime, the favorite April pastime of die-hard fans must be speculating on which streaking players are for real and which slumping players are not. Multiplying a hot player's first-month stats by six can produce some eye-popping numbers, not to mention more than enough hot air to keep the media's colorful balloons inflated.

A good way of testing whether individual April player statistics have any more significance than any other month is to look at the consistency of a couple of key indicators. By isolating each month of the season and comparing it to past stats for the other five months, it should be apparent if April stats showers are remarkable for any other reason than the fact that they occur in April.

Batters can be tested for consistency on a month-to-month basis by using On-Base Plus Slugging (OPS), which combines their slugging stats and their on-base percentage (which, of course, includes their batting average). The study covered the past seven full seasons (1998-2004), a period that started with the expansion to 30 teams and the realignment of the leagues – and which includes all but the first year of interleague play. Minimums of 100 plate appearances or batters faced were set to eliminate the wild swings in performance that would be true for those who played only a few games.

For pitchers, opponents' OPS (OOP) is used because wins, losses and saves are highly dependent on each pitcher's run support and opportunities. Testing relief pitchers for consistency when they normally pitch less than 20 innings per month is not really worthwhile – especially when the marquee stat for relievers is saves. The closer gets the vast majority of each team's saves until he is replaced by a different closer, at which point the former closer's saves essentially go to zero.

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